Gas - Properties of Gas, Conversions and Pipe Sizing Flashcards
What is the expansion ratio of Butane?
235 ft³ : 1
What is the expansion ratio of Propane?
270 ft³ : 1
What is the expansion ratio of Natural Gas?
600 ft³ : 1
What is the flame speed of Natural Gas?
25” / Second
What is the flame speed of Propane?
32” / Second
What is the flame speed of Butane?
33” / Second
What is the name of the odourant that they put into Natural Gas to give it the distinct smell?
Mercaptan.
Propane and Butane are often referred to as what types of gases?
LP Gases.
Liquefied petroleum.
What is considered low pressure in the world of gasfitting?
1/2 psig or less.
14” water column or less.
What is considered low volume in the world of gas fitting?
400 Mbh or less.
400,000 Btuh or less.
What is the manifold pressure in gas systems?
Natural Gas: 3.5” w.c.
Butane and propane: 11” w.c.
1 kW equals how many Btu’s?
3412.
1 m³ equals how many ft³?
35.31
1 psi equals how many inches water column?
27.72
1 psi equals how many feet of head?
2.31
1 psi equals how many kilopascals?
6.895
1 psi equals how many ounces per square inch (OSI)?
16.
1 psi equals how many inches of mercury?
2.04
The amount of energy (heat) in a given volumn is the definition of?
Calorific value.
What is the calorific value of air?
0.
State the calorific value of Natural Gas in the four different ways that we may need to refer to it?
1000 btu / ft³
0.293 kW / ft³
35,310 btu / m³
10.35 kW / m³[][]
What is standard pressure?
State your answers in both psi and kPa.
- 7 psi.
- 325 kPa.
What is standard temperature?
State your answer in both Celcius and Fahrenheit.
15°C.
60°F.
When calculating the LMR (longest measured run) where does the calculation start and where does it end?
It starts at the gas meter or regulator and ends at the furthest appliance.
When are you required to add fittings into your calculation?
On a system that’s 2 psig or greater.
Which of the following gases is considered to be inert?
A. H20.
B. N2[]]
C. O2[]]
D. CH4.
B. N2.
